<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<style>
  body {
    margin: 0;
    padding: 0;
  }

  main {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
    background-color: #24262D;
  }

  .loader {
    --loader-size: 50px;
    --loader-border-size: 4px;
    --loader-border-color: white;
    width: var(--loader-size);
    height: var(--loader-size);
    border: var(--loader-border-size) solid var(--loader-border-color);
    border-top-color: transparent;
    border-right-color: transparent;
    border-bottom-color: transparent;
    background-color: transparent;
    border-radius: 50%;
    position: relative;
    animation: rotateX 1s infinite linear;
  }

  .loader::before {
    content: "";
    border: var(--loader-border-size) solid var(--loader-border-color);
    border-top-color: transparent;
    border-left-color: transparent;
    border-bottom-color: transparent;
    background-color: transparent;
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 2px;
    right: 2px;
    bottom: 2px;
    animation: rotateX 0.5s infinite linear reverse;
  }

  @keyframes rotateX {
    from {
      transform: rotateZ(0deg);
    }

    to {
      transform: rotateZ(360deg);
    }
  }
</style>

<body>
  <main>
    <span class="loader"></span>
  </main>
</body>

</html>